johnson



UNTTE sTaTns TATnNT onnrcn.

J. B. JOHNSON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO JNO. SPARROVV, OF

PORTLAND, MAINE.

PUMP.

Speccaton of Letters Patent No. 30,825, dated December 4, V18.60.

T o all whom it may concern:

Be it known that I, JAMES B. JOHNSON, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Pumps; and

I do hereby declare that the following is a full, clear, and exact description of the same, reference being `had to the accompanying drawings, forming part of this specification, in which- Figure l, is a longitudinal elevation partly in sect-ion, of a steam pump constructed according to my invention. Fig. 2, is a plan View of the same, and Fig. 3, is a transverse section vtaken in the plane indicated by the line m, in Fig. l.

Similar letters of reference indicate corresponding parts in the several figures.

My invention is more particularly applicable to steam pumps for steam lire engines, and other purposes, but is also applicable to pumps worked otherwise than by steam power.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction' and operation:

A, is the reciprocating barrel bored internally and turned externally o f cylindrical form and fitted to work within the two stationary abutmentsD, D', which separate the inlet chamber F, and the outlet chamber G, of the pump, said abutments being bored out truly in line with each other, that the barrel A, may work freely within the two.4 outlet chambers, may be made of a suitable casting suitably cored out. The inlet chamber consists of a cylindrical cavity larger than the exterior of the pump barrel, formed between the abutments and has the inlet pipe f, at the bottom, and the outlet cham ber consists of two annular cavities surrounding the abutments, and connected by a hollow chest on the top of which is arranged the outlet pipe Gr, and the larger air vessel H within which is arranged the smaller air vessel N, of the inlet chamber. The abutment D', is closed, by a movable head a, and the other one D, through which the barrel A, projects some distance is fur- The abutments and the inlet and nished with a stufling box I, to prevent the escape of water round the barrel. In each abutment there is a port e, which may extend all round it, or instead of such continuous ports, two series of ports as shown in Fig. 8; and in the barrel A, there are two series of ports B, B, each of which series extends nearly all around, having only sufficient metal left between the several ports to keep the barrel entire, the two series being at such distance apart, less than the distance between the ports e, of the abutments that either series may be brought into communication with the abutment port c, at its own end of the pump, while the other series communicates with the inlet chamber F. Thebarrel A, 'it will be understood by reference to Fig. l, combines with the abutments to separate the inlet chambers, from the discharge chamber, and the only communication between the said chambers is through the ports B, and e, and through the interior of the barrel.

l?, is the piston or plunger fitted to the barrel A, and having its rod p, passing through the stationary head J, which is fitted like a piston to the interior of the barrel to close the outer end thereof, and whichv is furnished outside of the barrel with a. stuffing box g, to prevent the escape of water round the rod. This head is held in place by two rods O, O, which connect dit with the steam cylinder Y, or with any stationary part of the apparatus outside of the pump.

The plunger rod p, constitutes also the rod of the piston of the steam cylinder Y, by which the-pump is driven and is furnished with a crop head Y, which is fitted lto work on the stationary guide rods S, S,

which connect the pump casingv with the steam cylinder. The said crop head is also connected by two connecting rods 6, 6, with two crank pins T, T, carried by two fly wheels I, I, on a shaft C, which works in bearings at the back of the steam cylinder, said shaft having its axis transverse to, but in the same plane with the axis of the piston rod, and deriving a rotary motion from the piston rodl through the connecting rods having such a throw as to give the barrel a reciprocating movement, of such length as to bring each series of ports B, B, of the barrel in turn into communication with its respective port e, inthe abutment. The length of stroke of the plunger P, is such that it will just arrive at, or nearly at the edges of the abutments Gr, G. The cross head K, 'of the barrel A, carries the rod R, which works the slide valve of the cylinder.

The operation is as follows. The shaft C,

lhaving rotary motion imparted to it, either by the steam piston as before described or by other means, the plunger P, and barrel A,

'have each a separate and independent reciprocating motion imparted to them, the movement of the barrel in either direction, commencing just before the plunger has completed half its stroke. Fig. 1 represents the plunger as moving in the direction of the arrow marked upon it, havingnearly made half stroke, and the barrel having just completed its stroke in the opposite direction and commencing its return with the plunger. The water is now flowing from the inlet or suction chamber F, through the ports B, at the left hand, end of the barrel into the barrel, following the plunger, and it is being forced from before the plunger through the ports B and e, at the other end into the discharge chamber G. When the plunger shall have completed its stroke, the barrel A, will have made a little more than halfstroke, and the distance between the outer or furthest edges of the two series of ports B, B, being a little greater than the distance between the inner or nearest edges of the two ports, or series of ports e, e, there will be communication between the barrel, and the discharge chamber on each side of the plunger, and the latter will pass its center or in other words will have the direction of its motion changed, while in equilibrio, but yet the water is no case permitted to flow back into the inlet chamber as the ports B, B, are intended to Y be not quite so wide as the portions of the let chamber.

abutments between the ports e, e, and the in- As the barrel continues its motion forward, now moving in the opposite direction to the plunger, it opens communication between the inlet-chamber and the barrel at the right hand side of the plunger, and enlarges the communication between the barrel and t-he outlet chamber on the opposite side of the plunger. Itwill be thus understood that when the plunger is at half stroke, and moving at its greatest speed the barrel is in position to give the greatest opening to the inlet chamber behind the plunger, and to the discharge chamber in front of the plunger, and not only this but it (the barrel) is at Athat time working at its slowest speed, and so preserves nearly the full opening during that part of the stroke of the plunger in which it suffers but little 'diminution of velocity. The opening of the ports is in fact'at all times in proportion to the velocity of the plunger, and as the barrel A, works in equilibrio, both within the inlet chamberand vdischarge chamber, and the direction` of the movement of the plunger changes while it is in equilibrio, the movements of'the pump are easy and the flow of water through itfree, and hence it may be worked at a much higher velocity than pumps with'flat slide valves or valves working from and to their seats.

By the arrangement of the smaller air vessel N, of the inlet chamber F, within the larger air vessel H, of the discharge chamberG, it is brought directly over the chamber F, and hence it will compensate promptly for any change of velocity in the water flowing into and out of the said chamber and into the pump barrel A, and by the arrange ment of the fiy wheels as described, with their heaviest rsides opposite to the main crank pins, the eect of the motion of the water in the pump, and the momentum of the working parts are counterbalanced, and hence longitudinal oscillation is prevented; and by arranging one fly wheel on each side of, and at equal distances from the axis of the plunger and barrel all lateral oscillation is prevented, and by these means combined the pump ismade to possess special advantages for steam ire engines, and for any other purpose in which an easy and steady motion is required.

What 1 claim as my invention and desire to secure by Letters Patent is l. Having the outside cylinder divided into three compartments G, Gr, F, (separated by the abutments D, D,) which entirely surround the moving barrel A, as shown and described so that said cylinder A, will work in equilibrio.V 2. The extension of the moving barrel A, beyond its outer cylinder so that said cylinder may be operated by the application of proper force to said exterior end all as herein shown and described.

3. The arrangement of the chamber N, directly over the suction chamber F, so as to conduct the water in a direct line to the Vacuum chamber all as herein shown and debarrel of the stationary piston head J, when scribed. constructed and loperating as and for the 10 4. The combination of the barrel A, with purpose herein shown and described. the Valve rod R, as herein shown and de- J. B. JOHNSON. 5 scribed so that the same eccentric that drives Vtnesses:

the slide valve will also operate the barrel EDUARD FOX, A, all as set forth. 4I. B. HUBBARD,

5. The employment Within the moving FnEDERlCK FOX. 

